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中文核心期刊

基于导波传播特性的锂离子电池荷电状态研究

Study of lithium-ion battery state of charge based on propagation characteristics of guided waves

  • 摘要: 锂离子的摇摆过程致使电极力学性能呈现动态化特征, 从而影响了锂离子电池中的声传播特性。针对多层多孔的锂离子电池结构, 引入强鲁棒性的状态矩阵与勒让德级数联合法及经典的Biot理论, 同步考虑了因颗粒的局部电流密度、锂离子扩散过程与应力之间的相互影响而引起的电化学与力学的物理耦合效应(即力化耦合效应), 以特征值–特征向量的形式诠释锂离子电池中导波传播特性与荷电状态之间的内在联系。基于此, 搭建超声导波实验检测系统, 研究测量并提取定制软包钴酸锂电池中时域及频域特征参数的实验方法, 同时将渡越时间与理论计算结果相互验证, 表明测量分析方法可行。此外, 探究了不同放电倍率对锂离子电池声学特征参数的影响规律, 以实现锂离子电池老化失效潜在因素的声学分析, 为锂离子电池运行状态的无损检测与评价提供了研究路径。

     

    Abstract: The swing process of lithium-ion results in dynamic electrode mechanics, which affects the propagation characteristics of acoustic wave in lithium-ion batteries. The robust state-vector formalism, the Legendre polynomial method, and the classical Biot theory are introduced for multilayer porous lithium-ion battery structures. Meanwhile, the chemo-mechanical coupling effects are considered simultaneously in the model, mainly due to the physical coupling effects caused by the interaction between the local current density of the particles, the lithium-ion diffusion process and the stresses. Finally, the relationship between the propagation characteristics of guided waves and the state of charge in lithium-ion batteries is interpreted in the form of eigenvalue-eigenvectors. An ultrasonic guided wave experimental detection system is built, and the experimental method of measuring and extracting the time- and frequency-domain characteristic parameters in customized batteries is studied. The time of flight and the theoretical calculation results are then verified against each other, indicating that the measurement and analysis method is feasible. Furthermore, the influence law of different discharge rates on the acoustic characteristic parameters of lithium-ion batteries is investigated to realize the acoustic analysis of potential factors of aging failure of lithium-ion batteries. This provides a research path for the non-destructive testing and evaluation of the operational status of lithium-ion batteries.

     

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